Under the Immigration and Nationality Act, foreign nationals seeking entry into the United States undergo a vetting process to ensure that they satisfy the numerous requirements for admission. The Act vests the President with authority to restrict the entry of aliens whenever he finds that their entry “would be detrimental to the interests of the United States.” President Trump signed Executive Order No. 13769. Homeland Security was directed to conduct a review to examine the adequacy of information provided by foreign governments about their nationals seeking to enter the United States. The order suspended for 90 days the entry of foreign nationals from seven countries-Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen-that had been previously identified by Congress or prior administrations as posing heightened terrorism risks. The District Court for the Western District of Washington entered a temporary restraining order blocking the entry restrictions, and the Court of Appeals for the Ninth Circuit denied the Government’s request to stay that order. The President revoked EO-1, replacing it with Executive Order No. 13780, which directed a worldwide review. These interim measures were immediately challenged in court. The District Courts for the Districts of Maryland and Hawaii entered nationwide preliminary injunctions barring enforcement of the entry suspension, and the respective Courts of Appeals upheld those injunctions, albeit on different grounds. The Supreme Court granted certiorari and stayed the injunctions-allowing the entry suspension to go into effect-with respect to foreign nationals who lacked a “credible claim of a bona fide relationship” with a person or entity in the United States. After completion of the worldwide review, the President issued Proclamation No. 9645. Invoking his authority under 8 U. S. C. §§1182(f) and 1185(a), the President determined that certain entry restrictions were necessary to “prevent the entry of those foreign nationals about whom the United States Government lacks sufficient information”; “elicit improved identity management and information-sharing protocols and practices from foreign governments”; and otherwise “advance [the] foreign policy, national security, and counterterrorism objectives” of the United States. Proclamation §1(h). The Proclamation exempts lawful permanent residents and foreign nationals who have been granted asylum. §3(b). It also provides for case-by-case waivers when a foreign national demonstrates undue hardship, and that his entry is in the national interest and would not pose a threat to public safety. Ps are the State of Hawaii, three individuals and the Muslim Association of Hawaii. The three individual plaintiffs are U. S. citizens or lawful permanent residents who have relatives from Iran, Syria, and Yemen applying for immigrant or nonimmi grant visas. Ps argue that the Proclamation contravenes provisions in the Immigration and Nationality Act (INA) and violates the Establishment Clause of the First Amendment. The District Court granted a nationwide preliminary injunction. The Court of Appeals for the Ninth Circuit granted a partial stay, permitting enforcement of the Proclamation with respect to foreign nationals who lack a bona fide relationship with the United States. The Supreme Court stayed the injunction pending disposition of the Government’s appeal. The Court of Appeals held that the Proclamation exceeds the President’s authority under §1182(f). It held that the entry restrictions also contravene the prohibition on nationality-based discrimination in the issuance of immigrant visas. The Supreme Court granted certiorari.